Torque­limiting Backstop (Special Design) - Siemens FLENDER K SH Series Assembly And Operating Instructions Manual

Note
The locking direction can be changed by turning the cage around. If a change in locking direction is
required, Siemens should always be consulted.
NOTICE
Material damage
Risk of damage to or destruction of the backstop and/or the gear unit through incorrect direction of
rotation.
Do not allow the motor to run adversely to the blocking direction of the gear unit.
Observe the notice fixed to the gear unit.
Before connecting the motor, determine the direction of rotation of the three­phase current supply using
a phase­sequence indicator. Connect the motor in accordance with the specified direction of rotation.
NOTICE
Material damage
Damage to or destruction of the backstop possible through increased wear during operation at speeds
below disengagement speed.
If the gear unit is operated at speeds below the speed at which the backstop disengages, the backstop
must be regularly replaced.
The frequency of replacement is stated on the dimensioned drawing of the gear unit and on a plate on
the gear unit. This plate is attached to the gear­unit housing close to the backstop.
5.7.1 Torque­limiting backstop (special design)
For certain requirements, the gear unit can be fitted with a mechanical backstop. The backstop permits
only the specified direction of rotation during the operation of the unit. The direction of rotation is marked
by a direction arrow on the input and output side of the gear unit.
The backstop is fitted oiltight on an adapter flange on the gear unit and integrated in its oil­circulation
system.
A torque­limiting backstop is available for special applications, e.g. dual drives. This backstop is
a combination of a backstop with centrifugally operated sprags and a brake. The slipping torque is set by
a number of compression springs.
This "slipping" will protect the gear unit and the sprags of the backstop from inadmissibly high stresses
during reverse rotation. An even load distribution onto both gear units is achieved during reverse rotation
when using dual drives.
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